Its chemical symbol is CH2FCF3. Spray it deep, and let it sit for a few minutes. I think so. ThanksPaul -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. By using a qualified a/c shop with the proper equipment you odds are in your favor of having the job done correctly the first time. So to keep things simple and to avoid controversy and politics we have R134a. In a car ac, using this type of freon 20 years ago was difficult. I'll put the relay on for that. Some say that a chemical reaction can harm the A/C very badly as R134a reacts with mineral oil in some way. Ask Our Pros-Owner Assistance - NO DIY advice will be given. ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. Read on for more information about using automotive r134a in a refrigerator and vice versa. Is there a graph? hardly noticable. The flammables have hydrocarbons. Gnats & mosquitos will clog deep. Compatible with multiple applications: The major reason for the introduction of R134a was to replace R12, so it functions perfectly in the same range of applications like rotary, screw, and centrifugal compressors for air conditioning and refrigeration. The aux fan seems to be working fine - it switches on occassionally. It's best to determine on a case-by-case basis while monitoring system pressures and output air temperature. Thanks so much Bohica - you've save me many more hours of fruitless speculation. Pound for pound R134a is a more efficient refrigerant than R12, however it runs at higher pressures in some aspects and therefore requires more effective condensing. Generally you follow the refrigerant flow moving from connection to connection, component to component, and you sniff the a/c vents to check for evaporator leaks as well. It is also used in automotive car conditioning and the plastic industry. The name of the oil is Polyol Ester (POE). At the moment, the ac is acting up - will work fine for about 15 minutes and then slowly the vent temperatures rise until the compressor switches off. That's a lot isn't it? R-12 is no longer used or produced in many countries and remaining quantities have skyrocketed in price. Unfortunately, the oil only mixes with the refrigerant as a liquid. Generally the system will be initially charged with approximately 80% to 85% of the original amount of R12, using R134a. A final difference is that most (though not all) R-1234yf cars will have a Suction Line Heat Exchanger. Or is there always room for improvement, the more the merrier. Skin contact: If the R134a (liquid) comes in contact with your skin, it could cause a burn. Recovery & flushing is the only way out of an oil overcharge in your vehicle.B. The pressure at low temperatures is nearly the same between 12 and 134a. The cost of recharging the air conditioner is between $150 to $500. You may need to adjust the valve in a bit to get desired superheat. This refers to BTU's (heat) moved per pound of refrigerant moved. The old compressor used R12 and the new unit will be R134a. R134a refrigerant is about 10% less efficient in moving heat than R12! However, R12 refrigerants are still used as fire retardants in aircraft and submarines. R12 contains a chemical called chlorine that destroys the ozone layer, thereby causing potential environmental risk. The car never overheats, if that has any import. The higher the ambient temperature the higher the high side pressure. We sometimes use a relay switched from the compressor clutch to run fans. About four or five years ago, I guy with an MB came here with the same problem, that tread was over six pages long. Usually, mechanics charge around $200 for conversion. Hot coolant migrates up through the core by convection (is that the word? They can be mounted quite easy,and there is a mounting kit that helps to hang it. The whole trick is to sit there in those steam boxes and not perspire, it's vulgar to perspire when driving on public roads.If you want esteem, drive an MB, if you want comfort with 60*F interiors in a 125*F environment, get a Caddy. R1234yf is more environmentally friendly and has a global warming potential of 4. But I've read that these car's didn't do too well in the a/c stakes, so that might just be as good as it gets. We chose to use 5-6 ounces of oil to be on the safe side: 3-4 ounces for the compressor, 1 oz of oil for the drier and another ounce of oil for system losses. That switch should close @ 52c. These cheap kits usually have a few cans of R134a (either 12 ounce or 16 ounce), maybe an extra can of refrigerant oil, a few generic R134a charge port adapters and maybe some o-rings. 3) A TXV optimized for 134a will be ok with R12. The newer valves and switches will work with both refrigerants. Therefore, the higher the factor of the chemical (compound), the greater its effect on global warming. Replied by Rich928 on topic R12 or R134a. Do a pre-inspection and then Evacuate (vacuum down) the system, the longer the evacuation the better but there is a point of diminishing return, 2-3 hours is generally very good. difference between r12 and r134a expansion valve. The system has been previously converted to R-134a. Its chemical symbol is CCl2F2. 4) Repeat step 2, making sure it will fit. I'll report back on the aux fan on performance next. R12 is otherwise called dichlorodifluoromethane is a colorless gas (chlorofluorocarbon halomethane (CPC) that is used as an aerosol spray propellant and a refrigerant, and is soluble in organic solvents. El maig de 2016, un grup damics van crear un lloc web deOne Piece amb lobjectiu doferir la srie doblada en catal de forma gratuta i crear una comunitat que inclogus informaci, notcies i ms. R-401b is the mixture by weight of 61% R22, 11% R-152a and 28% of R-124. I don't think it has any air dams or seals, I'll check to make sure. Can I use the one for the R-12? Is there a source of valves by, say, eaton number? of coiled cap tube on VCR system with R134a. Add to cart. Expansion Valve. R12 was once used in many air conditioning units as a refrigerant or cooling agent. So that indicates it is cooling well there doesn't it? Here are the basics for converting a system that does not have a charge of R12, its empty. Below are the major differences between R134a and R12: Chemistry The chemical composition of R12 and R134a differ. If it splashes inside the eye, it could lead to a serious eye problem. Any suggestions, or do you need to know the hi/lo readings? If you're getting a R134a compressor, might as well finish the job - replace the receiver/dryer, flush everything else, and convert to R134a anyhow. Stopleak is also risky. It may take a couple of tries to get things really clean.The laser is usually close on clean surfaces, but I prefer a T/C. R134a is called tetrafluoroethane (HFC). Paul -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. Is there a difference between a R134a expansion valve and an R12 TXV? And I already have so much time and money in this a/c project that I REFUSE to cut any corners as small as a TEV.It doesn't help that most people in the business (at least that I come in contact with, present company excluded, of course!) The system has been previously converted to R-134a. R134a requires the use of synthetic oil! The system will be checked for gross leaks while under vacuum. -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. If your a/c system is empty/low on refrigerant, if your system has a leak or if you need to open the system, then now is the time to decide which refrigerant you want to use. I'm doing one thing at a time so I know what the cause was. Plus, not releasing the chemical into the air is morally justifiable. The ozone depletion potential of a chemical is a factor that shows the level of degradation itll cause to the ozone layer that surrounds and secures the earth from harmful radiation. With R-12, 30 is 28.4psi and 40 is 36.9psi, for a difference of 8.5psi. On this website we are addressing only R134a and not other suggested drop in replacements. There are two hoses listed, R-12 64-53-1-377-821 for $72.50, and R-134a 64-53-8-391-051 fro $262.50. . It won't be optimal, though.On some/many valves, you can adjust them, but that might make matters worse unless you really know what you're doing (which I don't!).RegardsGeorge. R-134a XV for R-134a use. The oil is spread all over your system when it is at rest. In large application systems, the vapor density of this refrigerant is usually high. The common problem when converting from R12 to R134a is lack of knowledge or equipment. Then, subtract that result by 0.25 pounds to get the proper amount of R134a charge. The Wikipedia explanation for expansions valves cited in Frank's thread says that the gas inside the bulb in the metering valve is the same as the refrigerant in the system. Your decision could be made based on economics, environmental concerns, or both. It won't be optimal, though. R12 systems used mineral oil, but unfortunately mineral oil doesn't dissolve in R134a. Unfortunately, the R12 refrigerant doesnt always blow cold air. and recharged with mineral oil and 2.2 lbs R12. ambulance tailgate conversion The P H and T cond,sat of the HR12 at a T oa of 40 C were higher than that of the R134a, resulting in a higher P e than that for the R134a. The butylcellusolve or the citrus solvent will dissolve the carcass in a few minutes. 10,000BTU conduction heating? (You must log in or sign up to reply here. To bless the system the technician should attach a R134a sticker somewhere in the engine compartment to note the car is using R134a. shown for the parallel flow, aluminum condenser that is listed. R12 and R22 are both now banned by the EPA in the United States. The first vehicle that used the R1234yf refrigerant was the 2013 Cadillac XTS. You can also check the Aux fan in your case. As an example, let's say the R12 charge specification is listed at 2 lbs. I bought a relay to put on it connected to the compressor clutch. At this time you can still find R12, but, because it is no longer produced, availability is limited to current inventories and the price per pound is greater than R134a. With R12 you use to check to see if the site glass was full, if it had bubbles it meant you had a low charge. Please enter a valid email address for yourself. When the temperature is reduced to-7C or below, the plants ability to cool the airdrops significantly. Consider using the newer valve, even with 134a stamped on the valve. A discussion of the relationship between valve capacities and superheat set-tings can be found in Bulletin 10-9. Comparatively, larger R134a molecules should take more space, and a smaller amount might be required. Kommentare . An orifice tube is just a fixed nozzle that pisses refrigerant into the evaporator without any sort of feedback. Swapping the components isnt a herculean task, but recharging the AC is a challenge. The original expansion valves work very well with R134a. Also, R134a cylinders are light-blue in color. Can I order a valve based on the original eaton number? By after changing just about everything, he got what was termed, satisfactory cooling. I could easily be over at least 2 - 3 ounces over on the oil. The next piece of equipment to track down leaks is a leak sniffer. Stay home and grill your own steaks and stir your own martini. and an evaporator core and expansion valve that are optimized for R134a . You'll get marginally better performance out of the change as the expansion valve is matches the refrigerant characteristics. At the time I thought nothing of it, but now I am thinking maybe that is contributing to the system not working as well as it could. The difference between R12 and r134a is the BTU carrying capability. look at the difference! There are significant differences between R12, R134a, and R513A, which must be considered when handling, processing, applying, or retrofitting with these refrigerants. They examined the two configurations of capillary tubes i.e. What effect would it have on performance, if any?At the moment, the ac is acting up - will work fine for about 15 minutes and then slowly the vent temperatures rise until the compressor switches off. Jun 17, 2011. With the knowledge of the differences, youll be able to draw a comparison between R12 vs R134a efficiency. Even with proper fan operation, missing seals & air dams can effect condensor effeciency. I have just bought gauges. difference between r12 and r134a expansion valve. The R134a compressor has a 1/8" step in on the high side port. I have the original (R12) style expansion valve in the Maverick AC system. For R12, its mineral oil. How an A/C Expansion Valve Works. This implies that the discharge pressure of the compressor should be moderate so it can produce the refrigerants condensation in the condenser at the atmospheric temperature. The #1 question asked by NEW MEMBERS. Most of all the differences gravitate to longevity, functionality, and safety. The only difference I can imagine would be the recharge connection. James10952001. Yes, this was a smokers car. Theres no problem with using R134a in a home air conditioning system because it is a hydrofluorocarbon that doesnt cause environmental harm. Don't like the sound of custom parallel condensor. We mention using ester type refrigerant oil. They would then make short "jumper hoses" to connect to the existing stock hoses, refit your old fan if there is a "pusher" fan, and recharge to specs. There are significant differences between R12, R134a, and R513A, which must be considered when handling, processing, applying, or retrofitting with these refrigerants. Also, it can be used with all types of compressors. Some compressor manufacturers or OEMs suggest PAG type oil for R134a. In cases such as this, the required capacity value of the expansion valve with R134a is reduced by 30% (correction factor 1.42). Are you sure you have an R4? leading to corrosion of expansion valves, capillary tube plugging, and compressor bearing . However, theyre still used in older plants, systems, and the automotive industry. The ARPA Zone/Open Membership Discussion Forums. R404a for freezing of product. Back in that era, my business associates drove those things, brand new, and maybe I should take my Cadillac instead, no they wouldn't be caught dead in a Caddy, people of our esteem should be driving an MB. 30 deg is pretty coldSystems generally run between 40 and 43 deg. It would make a big difference at idle ,in traffic!! Your average garage that works on a/c on the side probably would not have this. If he is not in the garage fixing challenging mechanical problems, he is writing automotive repair guides, buyers guides, and car and tools comparisons. He used thermostatic expansion valve and Capillary tube for analysis with R12. The exact amount will vary with each car. But, what is considered a good temperature differential across the condensor? R134a is NOT less efficient than R12 Actually R134a is more efficient. Warning: "continue" targeting switch is equivalent to "break".Did you mean to use "continue 2"? . -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a, Hi pdrayton- If you can remember the oil capacity that you found in all your research and post that, then bohica and others can have a better idea if you have too much; see if you can find that info! Vent temperatures slowly go down to around 50F with hi speed driving. R12 was once used in many air conditioning units as a refrigerant or cooling agent. Later model cars that come with 134A will have 134A only connectors. If liquid refrigerant were to exit the evaporator. R12 is CFC: Even though R12 is one of the most commonly used refrigerants, it is CFC. It does not "pool" to any degree in a large amount anywhere. Also, since R134a uses synthetic oil, it has a low global warming potential, unlike R12 which uses mineral oil which poses a negative environmental impact. Its chemical symbol is CH2FCF3. A slow loss of cooling at city speeds is usually related to condensor capacity & airflow issues. I am ordering new parts, and planning to convert my system to R-134a. You will be fine with a 134a-compatible TXV running R12. The safe high side pressures are determined with a PT (pressures and temperatures) chart. R134a compressors are substituted as new to retrofit the R12 system compressor part numbers with different height sealing washers. Fitting a PF condensor is not rocket science, but it requires some planning. If ambient is 90 (today) and the output of the condensor is 110, that's pretty good isn't it? Next I'll jumper the aux fan. The most common influences which effect the capability of R134a to perform well are the condenser, in some cases the the superheat setting of the expansion valve or the amount of R134a. Break out the new gauges and measure hi and lo at 1500rpm, and do the Merc FSM test to see how we're doing performance wise. After the system has been tested out it should be checked for leaks. However, the supply houses don't indicate a difference. The reason is that the vehicles, for instance, manufactured currently configure the engine for R1234yf refrigerant, making no provision for replacement. In the automotive world, the replacement for R12 was R134a. ing the expansion valve, a maximum opening superheat of 7F, and a standard factory air test superheat setting. R134a has the chemical formula CF3CH2F and is known as tetrafluoroethane.
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